Thanks everyone for sharing your opinions!
So all in all, a post without notifying subscribers is rarely seen... Hm, maybe when the staff changes the walls so that the flood of likes and comments doesn't show there (I would like to know of one person who actually WANTS to see those likes and comments on other's walls!), people may pay more notice to the wall content.
I find it really hard to post something on my wall because it just feels scary to click "notify subscribers" knowing the update will arrive to so many people's mail boxes! >_<; I always think again again if the post was really all that interesting.......
So far I have just posted 3 times on my wall with the notify on - first I was totally excited from a super cute caterpillar I had seen on a living invertebrates exhibition and just wanted the world to see how cute it was 
Second time I wanted to see if people would be interested in a comic I want to do so I sent a picture and only the third time it was something really important.
All these were posted at a 3 day interval and I had a terrible feeling I had annoyed the subscribers with these... But then again, I'm subscribed to a few comics that send notifications to their wall posts all the time it starts to feel a tiny bit bothering even to the hard-to-displease me
It's hard to find a balance, I guess.
At the same time, I was really surprised that people actually read those creator comments under an episode - for me it took a while to get used to paying attention to them. It's nice to learn what technique the creator used or what we should pay attention to, or as creator getting answers from readers to questions posted in the creator comment 